What is ibrutinib?

Targeted drugs aim to kill the type of cell that has turned cancerous or stop signals that make cancerous cells grow or divide. In lymphoma, the type of cell that becomes cancerous is called a ‘lymphocyte’ (a type of white blood cell that fights infection). There are several types of lymphocyte that can become cancerous. Ibrutinib targets B lymphocytes (B cells) and is therefore used to treat B-cell lymphomas.

Cells send and receive signals to other cells. Some of these signals keep cells alive and make them divide. There are lots of signalling pathways and signals are sent along one or more of these pathways. Ibrutinib (Imbruvica®) is a cell signal blocker<LINK> that targets a protein called ‘Bruton’s tyrosine kinase’ (BTK). BTK is a part of a pathway that helps B cells to stay alive and divide. Blocking BTK can make B cells die or prevent them dividing. This treatment can therefore stop the spread of cancerous B cells.

For people who have previously received other treatments for WM. Ibrutinib is given on its own.

For people who can’t have chemo-immunotherapy (chemotherapy with antibody therapy) as first-line treatment. Ibrutinib is given on its own.

European approval to use ibrutinib in CLL and mantle cell lymphoma was granted in November 2014. It was then extended to WM in May 2015. In 2016, the European Medicines Agency (EMA) expanded ibrutinib’s recommended uses for CLL.

Ibrutinib is being tested in further clinical trials in people with these types of lymphoma. This is to see if ibrutinib could work better in combination with other treatments, such as chemotherapy or antibody therapy (for example, rituximab). It is also being tested in other types of lymphoma. Use our searchable database to see if there’s a clinical trial that might be suitable for you at Lymphoma TrialsLink.

Is it available on the NHS in the UK?

Ibrutinib has been assessed by health authorities for some uses on the NHS in the UK. It is currently only available on the NHS for some people in certain parts of the UK.

Benefits

Ibrutinib is considered by many experts to be a ‘breakthrough treatment’ for some types of lymphoma. It gives higher response rates compared with other therapies for the same types of lymphoma. The main trials that led to approval of ibrutinib are briefly described below.

Benefits in mantle cell lymphoma

Mantle cell lymphoma that has relapsed or not responded to first-line therapy can be difficult to treat. However, the main study in this area showed that more than two-thirds of 111 people treated with ibrutinib responded to the treatment (their lymphoma shrank or disappeared).

A second study in 280 people compared ibrutinib with another cancer drug, temsirolimus, in people with relapsed or refractory mantle cell lymphoma. People lived for an average of 15 months without their lymphoma getting worse when treated with ibrutinib compared with an average of 6 months when treated with temsirolimus.

Benefits in chronic lymphocytic leukaemia (CLL)

Long-lasting responses have been seen in people with CLL treated with ibrutinib. In the main trial involving 391 people with relapsed or refractory CLL, ibrutinib was compared with ofatumumab, which is often used for people with CLL that has come back. One year after starting treatment, around 66 in 100 people taking ibrutinib had CLL that had stayed under control (this is called ‘progression-free survival’) compared with around 6 in 100 people treated with ofatumumab.

In a second study involving 269 people who hadn’t yet received any treatment for their CLL, ibrutinib was compared with the chemotherapy drug chlorambucil. After 1.5 years of treatment, around 90 in 100 people taking ibrutinib had CLL that had stayed under control compared with around 52 in 100 people treated with chlorambucil.

Adding ibrutinib to bendamustine and rituximab for people with relapsed or refractory CLL was also effective in a study involving 578 people. The risk of CLL progressing was reduced by taking ibrutinib instead of a placebo (dummy treatment).

Benefits in Waldenström’s macroglobulinaemia (WM)

A high response rate has also been seen in people with WM – about 9 in 10 people with WM responded to ibrutinib treatment in a trial in 63 people. This trial was a significant breakthrough for WM as it is an uncommon form of lymphoma and it is therefore difficult to recruit enough people to take part in a clinical trial. This trial led to the approval of ibrutinib for WM in Europe.

How is it given?

Ibrutinib is given as capsules which are taken orally (by mouth). Always follow the advice of your medical team when taking ibrutinib. You can usually take the capsules at home. Make sure you know how many capsules you should take – your recommended dose of ibrutinib is based on the type of lymphoma you have and your general health.

Swallow the capsules whole with a glass of water.

Never open the capsules, break them or chew them.

Take the capsules at about the same time every day.

Check the information you are given to find out what you should do if you miss a dose.

When is ibrutinib given?

Ibrutinib capsules are taken once daily. They can be taken every day until your lymphoma stops responding unless side effects are bad enough to make you stop treatment. You might be treated with ibrutinib for years.

Keep taking ibrutinib for as long as your medical team tells you to, even if you feel well. If ibrutinib is keeping your lymphoma under control, the lymphoma could get worse if you stop taking the drug.

Will I need any special tests while I am taking ibrutinib?

You will need to have blood tests to check your health, for example your blood cell counts, while you are taking ibrutinib. Your medical team might want you to have other tests depending on any other conditions you have or any side effects you develop. For example, you might have an electrocardiogram (ECG; a heart function test that records the rhythm and electrical activity of the heart) to check how well your heart is working. How often you need these tests depends on your individual circumstances such as other health conditions you have and how your lymphoma is responding.

Possible side effects

Only the most common side effects of ibrutinib are described on this page. This is not a complete list of side effects that have been reported. As ibrutinib is a new treatment, more information about possible side effects is still being gathered. There is limited information about late effects (side effects that only develop months or years after treatment has finished) of ibrutinib. Your team should discuss the most up-to-date information with you before you start treatment. Ask all the questions you have. Discuss with your medical team how ibrutinib might affect any other medical conditions you have. You also need to tell your medical team about any medicines, supplements or complementary therapies you are taking before you start any new treatment.

Most side effects experienced by people treated with ibrutinib are mild. In clinical studies, few people (about 5 in 100) had to reduce their dose of ibrutinib because of side effects. A similar number (about 5 in 100) had to stop treatment for this reason. Some side effects, such as diarrhoea, tend to occur early in treatment and then settle down if you continue to take ibrutinib, without needing to reduce your dose.

The most common side effects of ibrutinib, which can affect more than 1 in 5 people, are:

Although minor bleeding problems (for example bruising) are common, more serious events (for example a haemorrhage) can occur less commonly. Changes in heart rhythm can also present. These effects are described below.

Effects on blood

Ibrutinib can decrease the number of different types of cells in your blood. These effects are usually mild but can result in an increased risk of bleeding and developing infections. Ibrutinib can also cause a temporary increase in the number of lymphocytes (a type of white blood cell) in your blood. This does not normally cause any problems. Your medical team will check your blood cell counts regularly.

Bleeding problems

Ibrutinib can cause bleeding problems. These can be minor, such as bruising more easily, or serious, such as a haemorrhage. Bleeding problems could be caused by the effects of ibrutinib on platelet function. Platelets are found in your blood and help it to clot. It is not known why some people develop bleeding problems while others do not. People who take other drugs that affect platelets or drugs that thin the blood (anticoagulants such as warfarin) might not be able to take ibrutinib or may be monitored more carefully.

Tell your medical team if you notice any symptoms of bleeding problems so that you can receive prompt treatment: bloody or black stools (they look like tar), pink or brown urine, unexpected bleeding or bleeding that is severe or that you cannot control, vomiting blood or vomit that looks like coffee grounds, coughing up blood or blood clots, increased bruising, feeling dizzy or weak, confusion, changes in your speech, or a long-lasting headache. Your medical team might need to adjust your dose of ibrutinib or stop treatment if you experience significant bleeding problems.

Infections

Treatment with ibrutinib can lower your number of neutrophils (a type of white blood cell that fights infection). If you have neutropenia (low neutrophils), you may be at higher risk of getting an infection. Neutropenia experienced with ibrutinib is generally mild. People treated with ibrutinib commonly get infections including colds, sore throats and sinus infections. More serious infections, for example pneumonia, can occur.

It is also possible for infections that usually remain dormant in your body to flare up during treatment with ibrutinib. You might need extra monitoring if you have ever had hepatitis B (a liver infection).

Heart problems

Some people treated with ibrutinib develop heart rhythm problems. These are more likely in people who are at a higher risk of heart problems or who have had them in the past. In many cases, changes in heart rhythm are mild so you can continue taking ibrutinib but you may need to be monitored more carefully. Tell your medical team immediately if:

you feel like your heart is beating quickly and irregularly

you are light-headed, dizzy or faint

you have shortness of breath or any discomfort in your chest.

Your medical team will consider carefully whether ibrutinib is suitable for you if you already have heart rhythm problems or a relevant family history.

Who can’t have ibrutinib?

Some people will not be able to have ibrutinib because they are taking other medications or have other conditions. Make sure you tell your medical team about any medical conditions and any medicines you are taking. Your medical team may reduce your dose and monitor you more closely or recommend that you do not take ibrutinib if you have other conditions. These include liver problems, severe kidney problems or severe heart disease.

Some medications, including herbal remedies, can interact with ibrutinib and should not be taken with it. They could increase the risk of side effects or change the effect of ibrutinib. Give your medical team a list of all the medications you are taking. Make sure you include any vitamins, supplements or herbal remedies.

Drugs that affect blood clotting: At the moment, it is not recommended that ibrutinib is given with warfarin. Ibrutinib can be given with some other medicines that thin your blood or stop it from clotting but you will need to be monitored carefully because of an increased risk of bleeding. If you are taking warfarin, your medical team is likely to recommend that you change to a different blood-thinning medicine if you need to take ibrutinib. You shouldn’t take certain vitamins and supplements, such as fish oil or vitamin E.

Drugs that affect an enzyme called CYP3A4: CYP3A4 acts on many drugs to help remove them from the body, including ibrutinib. If you are taking a drug that interferes with the action of CYP3A4, it can decrease or increase the action of ibrutinib, depending on how the drugs work together. It is important that your medical team knows about all the medications you are taking as there is a range of drugs that can have this effect, including some antibiotics and herbal remedies such as St John’s Wort (used for depression and anxiety).

If you are about to have or have recently had surgery, you will not be able to take ibrutinib for at least 3 to 7 days before and after your operation, depending on the type of surgery recommended and your risk of bleeding.

Ibrutinib has not been approved for use in people under 18. You must not take ibrutinib if you are pregnant or become pregnant as it could damage your unborn baby. Discuss your treatment options with your medical team if you think you might be pregnant.

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Acknowledgements

With thanks to Professor Simon Rule, Consultant Haematologist, Derriford Hospital, Plymouth, for reviewing this information. Professor Rule is a paid advisor to the pharmaceutical company Janssen and receives research funding support.

We would like to thank the members of our Reader Panel who gave their time to review this information.